Detachable tool fastening means



July 22, 1958 v. WHISTLER ET AL 2,844,378 7 DETACHABLE TOOL FASTENING MEANS Filed July 5, 1957 Ma arJx w m$ N111 v E W J mm um GM Y B ATTO RNEYS.

United States Patent 2,844,378 DETACHA-BLE TOOL FASTENING MEANS Lawrence-V. Whistler andLawrence V. Whistler, Jr.,.

Kenmore, N. Y. a

Application July 5, 1957,'Serial-No. 670,040

8- Claims. (.Cl. 279-97) this apparatus a cylindrical punch is detachably secured in a punch holder, a stripper unit is detachably secured. to the cylindrical punch, and a hollow cylindrical die bushing is supported in a die holder, the bushing and. support being likewise preferably provi'ded with detachable securing means.

While reference is. had by way of example to the above-identified Whistler patent, and while the principles of the present. invention are illustrated inthe accompanying drawing and described in the following specification as applied to such punch and die units, it 18 to be. understood that the three detachable connections referred to above may be employed in a wide variety of punch and die mechanisms, innearly all of which the general problems of detachably securing a punch in a punch holder, detachably securing a stripper unit to apunch and-v detachably securing a die bushing in a die holder or die. shoe, present themselves- The most common prior art means for effecting the.

above detachable connections is by means of set screws. However, although setscrews are widely used for this general purpose, they are awkward and cumbersome in use and do not provide as certain and secure a locking arrangement as is desired.

According to the present invention a U-shaped member is mounted for horizontal movement in the female connecting part and is resiliently detained in either of two assembled positions. In one of the detained positions the legs of the U-shaped member extend through an annular groove in the cylindrical male connecting part to prevent relative axial movement of the parts, while in a second detained position the locking portions of the legs of the U-shaped member are clear of the annular groove in the cylindrical male member, whereby the parts may be readily separated by relative axial movement.

The accompanying drawing and the following detailed description set forth the detachable fastening means of the present invention in conjunction with a particulartype of punch and punch holder and die bushing and die holder structure and the stripper attaching embodiment is illustrated and described in conjunction with two known types of stripper units. However, as indicated earlier herein, these embodiments are by way of example only and the principles of the present invention may be applied to various punch and die arrangements and to the securement of various types of stripper units. Accordingly, the principles of the present invention are not "ice limited. to the. embodiments thus set forth by way of example and the scope of the invention is limited onlyas defined in the appended: claims.

In the drawing:

Fig, 1 is a general elevational view of a punch and die unit illustrating several instances of application ofone form. of the :attaching and securing means of the present invention;

Fig, 2 is a view taken similarly to Fig. l but comprising a. cross-sectional view on a vertical central plane and with a modified form of stripper unit;

Fig. 3 is a. cross-sectional view on the line IIIIII of Fig. 2; and

Fig. 4 is a view similar to Fig. 3 but with the locking member. in a. relatively released position.

The various parts illustrated in Figs. 1 and 2, with the exception of the stripper unit, are identical. These identical parts comprise mainly the punch holder, the punch, the die holder and the die bushing, and these parts will be given the same reference numerals in Figs. 1 and 2 Referring to both Figs. 1 and 2, the numeral 10 designates a punch holder of the general type shown in- Whistler Patent 1,986,036 and the numeral 11 designates a die' holder or die shoe of the type shown in that patent. It is well understood in the art that the punch holder 10 will normally be screwed or bolted to the movable platen of a power press and the die holder ,1].- will; be secured to the fixed bed or bolster of the press.

Punch holder 10' is vertically bored to receive a gen: erally cylindrical punch 13 and a companion die bushing 14 is disposed in a counterbore in the upper end of die holder 11, the latter being provided with a passage 15 for removal of scrap which. passes downwardly through the die. bushing 14.

In. Fig. 1 a stripper unit is designated generally by the numeral 17 and comprises a base or mounting block 18 and a work sheet engaging pressure plate 19. Compression coil springs 20 are interposed between block 18 and plate 19 and screws 21 are threaded into plate 19 at their lower ends and have head portions disposed in counterbores in block 18, all of the foregoing being conventional stripper unit construction which is well understood by those versed in the present art and need not be:

illustrated or described in further detail.

Fig. 2 shows a variant stripper unit designated generally by the numeral 24. In this instance an upper mounting block 25 and a lower work engaging pressure plate 26 are cemented or otherwise joined to a compressible rubber bushing 27.

It is to beunderstood that all of the foregoing is conventional or known construction in perforating units or similar punch and die holders and that the present invention is particularly concerned with quick detachable means for the various parts, which means will now be described.

The several fastening means are all generally similar and reference will 'be had more particularly to the. detachable fastener which connects stripper 24 with punch 13. in Fig. 2, this fastening arrangement being shown in further detail in Figs. 3 and 4. It will be noted that. punch 13 is provided with an. annular groove 30 and, referring to Fig. 3, a pair of parallel transverse bores 31 and 32 extend through mounting block 25 of stripper 24 in general alinement with groove 30, bore 31 having an enlarged counterbore 33 at one end thereof.

The locking element proper comprises a U-shaped or staple-like member 35 which has a pair of parallel leg members 36 and 37 which fit slidably in the bores 31 and 32, respectively. Leg 36 of U-shaped member 35 has a somewhat resilient reduced extension 38 which has a slightly rounded hook formation 39 at its outer end.

3 With the U-shaped member 35 in the position shown in Fig. 3 hook formation 39 engages over the outer end of counterbore 33 to resiliently detain the U-shaped mem-. ber in the position shown and in such position the legs 36 and 37 pass through annular groove '30 of punch member 13 to prevent relative axial movement of the parts.

Annular groove 30 may be of semi-circular cross-section, closely fitting the legs 36 and 37 in which case the member 35 will prevent axial movement of the parts in either direction. In the instance being described the groove 30 is of greater width in an axial direction to adapt punch 13 for other securing devices, but this greater width is merely incidental in the present instance. It will be noted that the legs 36 and 37 of fastener 35 engage the lower side of groove 30 thus preventing relative downward movement of stripper 24. Upward movement of the stripper is effectively prevented by abutment between the mounting block 25 of the stripper unit and the adjacent lower face of punch holder 10.

To release the stripper for removal from punch 13 it is merely necessary to withdraw the fastener 35 to the position shown in Fig. 4 against the releasable detaining effect of hook formation 39. This detaining elfect may be overcome by mere manual pulling force on the fastener but in most instances will most effectively be accomplished 'by inserting a screw driver or the like between the medial portion of the fastener 35 and the periphery of mounting block 25 (in the space marked A in Fig. 3) and exerting a prying force.

When the fastener 35 reaches the position shown in Fig. 4 the hook formation 39 will again exert a resilient detaining effect which, in ordinary usage, will prevent further withdrawal of the fastener 35. In this position it will be seen that the legs 36 and 37 are clear of the groove 30 of punch 13 and that accordingly relative axial separation of the punch 13 and stripper 24 may be readily accomplished. Further, the fastener 35 normally remains associated with mounting block 25. This not only prevents mislaying the fastener but prevents it from falling into the die parts where it might cause great damage if not removed.

Referring to Fig. 1, an identical fastener 35 connects stripper unit 17 to punch 13 and the block 18 of stripper unit 17 is bored and counterbored in the same manner as shown in Figs. 3 and 4 and described above in conjunction therewith. In Fig. l the fastener 35 and the bores which receive the same extend at right angles to the arrangement of Fig. 2.

Referring to both Figs. 1 and 2, the upper end of punch 13 is provided with a semi-circular groove 40 and a fastener 41 identical with the fastener 35 already described engages bore and counterbore formations in the punch holder which are the same as those illustrated in Figs. 3 and 4.

Still referring to both Figs. 1 and 2, the die bushing 14 of those figures has an annular groove of semi-circular or arcuate cross-section and a U-shaped fastener 45 engages the same just as in the case of the fastener 35 previously described in detail. The die holder 11 is provided with parallel transverse bores and a counterbore just as shown in detail in Figs. 3 and 4 and described in detail above in connection with the fastening between the stripper unit and the punch.

We claim:

1. A cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having an annular groove therein, said sleeve portion having a pair of parallel transverse openings extending generally tangent to said tool member at opposite sides thereof whereby said openings register with the annular groove in said tool member when the latter and said part are in desired assembled positions, a U-shaped locking member having a pair of legs disposed in said openings and adapted to pass through said annular groove to lock the tool member and said part against relative axial movement, a detent member comprising a reduced extension of one of said legs including detent means for arresting said U- shaped locking member before complete withdrawal from said openings but with said legs withdrawn from locking engagement with said annular groove.

2. A cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having an annular groove therein, said sleeve portion having a pair of parallel transverse openings extending generally tangent to said tool member at opposite sides thereof whereby said openings register with the annular groove in said tool member when the latter and said part are in desired assembled positions, a U-shaped locking member having a pair of legs disposed in said openings and adapted to pass through said annular groove to lock the tool member and said part against relative axial movement, and detent means for releasably detaining said U- shaped member in a locking position with said legs in engagement with said annular groove and in a partially withdrawn position wherein said legs are withdrawn from said annular groove.

3. A cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having a peripheral groove therein, said sleeve portion having a transverse bore extending generally tangent to said tool member in registry with the peripheral groove in said tool member when the latter and said part are in desired assembled relationship, a locking member comprising a leg disposed in said bore and adapted to pass through said peripheral groove to lock the tool member and said part against relative axial movement, a detent member comprising a reduced extension of said leg including detent means for arresting said locking member before complete withdrawal from said bore but with said leg withdrawn from locking engagement with said peripheral groove.

4. YA cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having a peripheral groove therein, said sleeve portion having a transverse bore extending generally tangent to said tool member in registry with the peripheral groove in said tool member when the latter and said part are in desired assembled relationship, a locking member comprising a leg disposed in said bore and adapted to pass through said peripheral groove to lock the tool member and said part against relative axial movement, and detent means for releasably detaining said locking member in a locking position with said leg in engagement with said peripheral groove and in a partially withdrawn position wherein said leg is withdrawn from said peripheral groove.

5. A cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having a peripheral groove therein, said sleeve portion having a transverse bore extending generally tangent to said tool member in registry with the peripheral groove in said tool member when the latter and said part are in desired assembled relationship, a locking member comprising a leg disposed in said bore and adapted to pass through said peripheral groove to lock the tool member and said part against relative axial movement, a detent member comprising a reduced extension of said leg terminating in a lateral projection for detent engagement with said sleeve portion for arresting said locking member before complete withdrawal from said bore but with said leg withdrawn from locking engagement with said peripheral groove.

6. A cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having a peripheral groove therein, said sleeve portion having a transverse bore extending generally tangent to said tool member in registry with the peripheral groove in said tool member when the latter and said part are in desired assembled relationship, said transverse bore having a counterbore at one end thereof, a locking member comprising a leg disposed in said bore and adapted to pass through said peripheral groove to lock the tool member and said part against relative axial movement, a detent member comprising a reduced extension of said leg terminating in a lateral projection for detent engagement with opposite ends of said counterbore for selectively arresting said locking member in a tool member locking position and in a partially withdrawn position wherein said leg is withdrawn from locking engagement with said peripheral groove.

7. A cylindrical tool member and a part having a sleeve portion fitting slidably thereon, said tool member having an annular groove therein, said sleeve portion having a pair of parallel transverse openings extending generally tangent to said tool member at opposite sides thereof whereby said openings register with the annular groove in said tool member when the latter and said part are in desired assembled positions, a U-shaped locking member having a pair of legs disposed in said openings and adapted to pass through said annular groove to lock the tool memberand said part against relative axial movement, a detent member comprising a reduced extension of one of said legs terminating in a lateral projection in detent engagement with said sleeve portion for arresting said U-shaped locking member before complete withdrawal from said openings but with said legs withdrawn from locking engagement with said annular groove.

member having a pair of legs disposed in said openings and adapted to pass through said annular groove to lock the tool member and said part against relative axial movement, a detent member comprising a reduced extension of one of said legs terminating in a lateral projection in detent engagement with opposite ends of said counterbore for selectively arresting said U-shaped locking member in a tool member locking position and in a partially withdrawn position wherein said legs are withdrawn from locking engagement with said annular groove.

References Cited in the file of this patent UNITED STATES PATENTS 1,182,934 Scott May 16, 1916 1,862,337 Emrick June 7, 1932 2,529,396 Hunt Nov. 7, 1950 

